Travelers love challenges. Most of them, fortunately, are less life-threatening than Mallory's. You could make a list . . .

In 1954, a group of very well-traveled travelers in Los Angeles did.

They weren't interested in scaling the tallest mountains, but their challenge was similarly lofty: to bring together people who had visited 100 or more of the world's countries and distinctive places.

And thus, the Travelers' Century Club was born. Today, there are 314 "countries" on their list, and 1,500 members on their roll. Earlier this year, I became one of them, having put a check mark next to "United States" and "Hawaii," "Canada" and "Cambodia," "Oman" and "Zanzibar" and 100 others.

What, you say? Hawaii and Zanzibar aren't countries?

Strictly speaking, the Century Club doesn't really count "countries." As the club's brochure explains its list of 314 destinations, "although some are not actually countries in their own right, they have been included because they are removed from parent countries, either geographically, politically or ethnologically." That's why you'll find Hawaii and Zanzibar on the list, along with two Turkeys (Turkey in Europe, Turkey in Asia), all four components of the United Kingdom (England, Northern Ireland, Scotland, Wales) and nine Antarctic outposts.

Though Centurions--as club members are sometimes called--can place-drop ("when I was in Eritrea . . .") with the most peripatetic of travelers, it isn't the bragging but the collecting that keeps them going.

According to Century Club Chairman Klaus Billep, whose own count stands at 270--with the addition earlier this year of North Korea--only about 10 members have visited all 314 destinations.

The club doesn't keep demographic information on members, but Billep, who is 62, says they tend, as would be expected, to be older and--"it's just Mother Nature"--female. Aside from the widowhood factor, though, women seem to be more adventurous. "I know there are some women who travel a lot whose husbands couldn't care less," says Billep. "[They'll say,] 'Who wants to go to Pitcairn?' "

The club has nine chapters, including one in Chicago, and it hosts regular social meetings and lectures. It also solicits "Info Files" from members about their recent trips. In May, the reports filed included "Afghanistan: Six Days in Kabul" and "British Indian Ocean Territory," a trip on which the participants' boat was boarded by suspicious British marines while a helicopter hovered overhead.

And, of course, there are the club trips--to places like Cuba, the Sahara, "central Asia-Stan countries," the Northwest Passage, Micronesia and "the hidden corners of the world," among other locales you aren't likely to be able to book through Apple Vacations. Coming up in 2003: a 16-night tour hitting the Netherlands Antilles, Venezuela, Trinidad, Guyana, Suriname, French Guiana and Brazil (that's seven countries, if you're counting), from $5,995.

There's an addictive quality to picking up, say, a Trinidad or a Guyana, as collectors can attest. I haven't taken any trips just to pick up countries, but the club has had a subtle influence on me. Some years ago I visited the United Arab Emirates--which, though they share a single UN seat, are actually seven individual emirates and are carried on the club's list as such--and I made sure to visit all seven.

Similarly, the Tribune's Travel staff does not go to an obscure country simply "because it's there," though together we have racked up a lot of countries over the years.

Besides my 106, here are our respective tallies: Travel writers Alan Solomon (56), Robert Cross (54) and Toni Stroud (25); associate Travel editor Carolyn McGuire (48); assistant Travel editor Phil Marty (12, but he's a relative newcomer). Adding in Alfred Borcover, a former Tribune Travel editor who's now retired but contributes a regular column, with his 98, and eliminating duplications, the total number of Travelers' Century Club "countries" that the Travel staff has visited is 166.

Just 148 to go.

BEEN THERE?

On the following pages are checklists of the 314 countries and separate entities in 12 regions as classified by the Travelers' Century Club, along with "bests" and other comments from Tribune Travel staffers.

- Tick off 100 or more of these countries/ entities, and you can join the club. Even the shortest visit--a port-of-call on a ship, a refueling stop on a plane--qualifies. Membership is $35 yearly, plus $100 initiation. Contact: Travelers' Century Club, Box 7050, Santa Monica, CA 90406-7050; 310-393-7419; www.travelerscenturyclub.org